All-optical characterization of carrier lifetimes and diffusion lengths in MOCVD-, ELO-, and HVPE- grown GaN
2007 (English)In: Journal of Crystal Growth, Vol. 300, 2007, Vol. 300, no 1, 223-227 p.Conference paper (Refereed)
The metrological capability of the picosecond four-wave mixing (FWM) technique for evaluation of the photoelectrical properties of GaN heterostructures grown on sapphire, silicon carbide, and silicon substrates as well as of free-standing GaN films is demonstrated. Carrier recombination and transport features have been studied in a wide excitation, temperature, and dislocation density (from ∼1010 to 106 cm-2) range, exploring non-resonant refractive index modulation by a free carrier plasma. The studies allowed to establish the correlations between the dislocation density and the carrier lifetime, diffusion length, and stimulated emission threshold, to reveal a competition between the bimolecular and nonradiative recombination, and to verify the temperature dependence of bimolecular recombination coefficient in the 10-300 K temperature range. It was shown that the FWM technique is more advantageous than the time-resolved photoluminescence technique for determination of carrier lifetimes in high quality thick III-nitride layers. © 2006 Elsevier B.V. All rights reserved.
Place, publisher, year, edition, pages
2007. Vol. 300, no 1, 223-227 p.
IdentifiersURN: urn:nbn:se:liu:diva-38848DOI: 10.1016/j.jcrysgro.2006.11.014Local ID: 45864OAI: oai:DiVA.org:liu-38848DiVA: diva2:259697